Siemens NMX3B800 Molded Case Circuit Breaker

Siemens NMX3B800 is an 800 A, 600 V three-pole molded-case circuit breaker designed for heavy‑duty protection in industrial power distribution. Part of the VL Series within the NMX family, this unit uses a thermal‑magnetic trip mechanism with a non‑interchangeable trip assembly for consistent protection. It is bolt‑on mounted and ships without lugs, enabling straightforward integration into Siemens panels and backplates. The NMX3B800 delivers a short‑circuit breaking capacity of 35 kA at 480 V and is rated for ambient temperatures up to 40°C, making it suitable for standard industrial environments. Its design supports reverse‑fed configurations and is intended to protect feeders and large motor circuits in 600 V systems, providing reliable overload and short‑circuit protection for heavy electrical feeders in distribution panels.